A Study on the Development of Two Ornamental Varieties of Ipomoea batatas Cultivated in Vertical Systems in the Northeastern Region of Europe

The Ipomoea batatas ornamental variety of the edible sweet potato is a decorative sweet potato with exquisite leaves, available in different varieties. Due to its numerous characteristics related to resistance, adaptability to environmental conditions, rapid growth, and aesthetic traits, it has attracted the interest of researchers. The purpose of this study is to investigate the growth and development behaviour of two varieties of I. batatas, namely 'Margarita' and 'Blackie', cultivated in vertical systems, to provide guidelines for their usage in green facade design. The physiological growth processes throughout the growing season were analysed by monitoring three biometric parameters (diameter, height, and leaf count), transpiration (dehydration rate), and the photosynthesis process (photosynthetic pigment content) for treated and control variants and four cardinal orientations (N, E, S, and W). Compared to the control and western orientation, which proved to be less advantageous, the northern orientation and treatment appeared to be the most suitable options for both varieties analysed. Also, the content of organic substances was more intense in the Cropmax-treated 'Blackie', especially on the northern facade, with the highest quantities of chlorophyll a (17.1%), chlorophyll b (9.1%), and carotenoid pigments (7.5%). In addition, the leaf dehydration rate, as well as the amount of free water loss, were reduced on the northern facade of 'Blackie'. Therefore, 'Blackie' can be recommended as a variety distinguished by its improved resistance to challenging environmental conditions, particularly drought.